By
Eric Sonstroem

Posted April 12, 2012

The circulatory system of a penguin's legs and feet has evolved to lose as little heat as possible.

What keeps penguin’s feet from freezing?
Penguins’ feet don’t freeze because of the blood circulating in them.

The circulatory system of a penguin’s legs and feet has evolved to
lose as little heat as possible, while keeping the penguin’s feet just
above freezing. One way a penguin’s feet hold onto heat is by
restricting the flow of blood in really cold weather. Actually, humans
can do this too. That’s why your hands turn whiter in cold weather,
there’s less blood in them.

Also, the tops of penguins’ legs work like a kind of natural
heat-exchanger, cooling the blood from their bodies on the way to their
feet, and heating the blood as it returns to their bodies. The arteries
and veins here become very fine and interwoven. That way the feet only
get pre-cooled blood, so there’s less heat to lose.

Friday, July 13, 2012

ScienceDaily (July 12, 2012)
— The continent of Antarctica is at risk from human activities and
other forces, and environmental management is needed to protect the
planet's last great wilderness area, says an international team of
researchers, including a Texas A&M University oceanographer, in a
paper published in the current issue of Science magazine.

Mahlon "Chuck" Kennicutt II, professor of oceanography who has
conducted research in the area for more than 25 years, says Antarctica
faces growing threats from global warming, loss of sea ice and landed
ice, increased tourism, over-fishing in the region, pollution and
invasive species creeping into the area. One of the longer-term concerns
that may present the greatest threat overall is the potential for oil,
gas and mineral exploitation on the continent and in the surrounding
ocean, the authors note.
Kennicutt says the Antarctic Treaty System that governs the continent
has worked well since it was established in 1962 and that 50 countries
currently adhere to the treaty, but it is under pressure today from
global climate changes and the ever-present interest in the area's
natural resources, from fish to krill to oil to gas to minerals.

"Many people may not realize that Antarctica is a like a 'canary in a
coal mine' when it comes to global warming, and Antarctica serves as a
sort of thermostat for Earth," he points out. "The polar regions are the
most sensitive regions on Earth to global warming, responding rapidly,
so what happens in Antarctica in response to this warming affects the
entire Earth system in many ways that we barely understand," Kennicutt
explains. "Antarctica contains over 90 percent of the fresh water in the
world, locked up as solid water in its massive ice sheets. Research
that develops fundamental knowledge and understanding of these complex
systems conducted in and from Antarctica is critical to understanding
many of the challenges facing Earth today."

In addition to conducting research in the area, Kennicutt is also
president of the Scientific Committee for Antarctic Research (SCAR),
formed in 1958 to coordinate international research in the region.
More than twice the size of the United States, Antarctica has no
cities, no government and no permanent residents. All who go to
Antarctica are short-time visitors, whether they are scientists,
personnel that support scientists or tourists. Antarctica is the
coldest, driest and windiest location on Earth and is the only continent
with no time zones.

"The Antarctic Treaty has worked well for the past 50 years, but we
need to rethink how best to protect the continent from a range of
growing of threats," Kennicutt adds.

"The treaty forbids oil or gas development, but it's possible that
could be challenged in the years to come. Until now, energy companies
have shown little interest in exploring the southern reaches of our
planet because of the harsh conditions, the distance to market and the
lack of technologies make it a very expensive commercial proposition.

"In the 1960s, most believed that drilling on the North Slope of
Alaska was not economical, and in less than 30 years, it became one of
the world's major sources of oil. Deep-water drilling today is practiced
worldwide and subfloor completion technologies are rapidly advancing,
so barriers in the past may soon be overcome increasing the threat to
Antarctica in the not-so-distant future."
Another problem -- melting ice from several areas of Antarctica -- is a very real concern today, Kennicutt adds.

"A report in the news last week shows that sea-level rise on the east
coast of the U.S. is occurring much faster than predicted," he notes.

"As the planet warms and the massive ice sheets break apart and melt,
sea levels could continue to rise dramatically, not only in the U.S.
but around the world. The ice sheets of Antarctica are known as the
'sleeping giants' in the ongoing debates about climate change and sea
level rise. Scientists have only rudimentary understanding of how and
when these 'giants' will contribute to sea level in the future."

He adds that the first explorers to Antarctica more than 100 years
ago would be surprised to see how things have changed in the region.

For instance, it has been proven there are more than 300 sub-glacial
lakes in Antarctica, some of them as big as the Great Lakes, and the
huge ice sheets in the area flow like rivers to the ocean. He adds that
growing tourism in the area and numerous scientific expeditions suggest
that the prospect of permanent human settlements is not out of the
question.

"All of these concerns pose serious challenges to conservation and protection efforts in Antarctica," Kennicutt notes.

"The bottom line is that we need to make sure that existing
agreements and practices that address and respond to these threats are
robust enough to last for the next 50 years, and that they truly provide
the necessary protection of Antarctica that we all wish for and that we
owe to future generations."

Story Source:

The above story is reprinted from materials provided by Texas A&M University, via Newswise. Note: Materials may be edited for content and length. For further information, please contact the source cited above.

Researchers have discovered a series of dinosaur eggs with a unique
characteristic: they are oval in shape. The discovery supports the
theory that birds and non-avian theropods, dinosaurs from the Cretaceous
Period, could have a common ancestor. (Credit: Image courtesy of
Universitat Autònoma de Barcelona)

ScienceDaily (July 12, 2012)
— Researchers have discovered a series of dinosaur eggs with a unique
characteristic: they are oval in shape. The discovery supports the
theory that birds and non-avian theropods, dinosaurs from the Cretaceous
Period, could have a common ancestor.

Before her death in December 2010, Nieves López Martínez,
palaeontologist of the Complutense University of Madrid, was working on
the research of dinosaur eggs with a very peculiar characteristic: an
ovoid, asymmetrical shape. Together with Enric Vicens, palaeontologist
of the Universitat Autònoma de Barcelona, the two scientists conducted
an exhaustive analysis of their discovery, recently published in the
journal Palaeontology.

The new type of dinosaur egg has been given the scientific name of Sankofa pyrenaica. The eggs were discovered in the Montsec area of Lleida, in two sites located on either side of the Terradets pass in Spain.

The South Pyrenean area is rich in dinosaur egg sites, most of which
correspond to sauropod eggs from the upper Cretaceous, dating back more
than 70 million years ago. During that period, the area was a coastal
area full of beaches and deltas which won land from the sea through
sediment accumulation. Sand and mud from that period gave way, millions
of years later, to the sandstone and marl where dinosaur remains now can
be found. On the beach ridges and flat coastal lands is where a large
group of dinosaurs laid their eggs.

The sites where the discoveries were made correspond to the upper
Cretaceous, between the Campanian and Maastrichtian periods, some 70 to
83 million years ago. The fossils found belong to small eggs measuring
some 7 centimeters tall and 4 cm wide, while the eggshell was on average
0.27mm thick. Most of the eggs found were broken in small fragments,
but scientists also discovered more or less complete eggs, which can be
easily studied in sections. The eggs found at the sites all belong to
the same species. The main difference when compared to other eggs from
the same period is their asymmetrical shape, similar to that of chicken
eggs. The more complete samples clearly show an oval form rarely seen in
eggs from the upper Cretaceous period and similar to modern day eggs.
Their shape is a unique characteristic of theropod eggs from the
upper Cretaceous period and suggests a connection with bird eggs. Non
avian dinosaur eggs are symmetrical and elongated.

Asymmetry in bird
eggs is associated to the physiology of birds: they take on this shape
given the existence of only one oviduct which can form only one egg at a
time. In this case the isthmus, the region in the oviduct creating the
eggshell membrane, is what gives the egg its asymmetrical shape.

Thanks
to this shape, the wider end contains a bag of air which allows the bird
to breathe in the last stages of its development. This evolutionary
step was still relatively underdeveloped in dinosaurs.
Thus, the egg discovered by UCM and UAB researchers may represent the
missing link between dinosaurs and birds. Only one other egg,
discovered in Argentina and corresponding to a primitive bird from the
same period, has similar characteristics. The discover supports the
theory that non avian theropods, the dinosaurs of the Cretaceous period,
and birds could have had a common ancestor.

Wednesday, July 11, 2012

The researchers aren't sure if the king penguins are
acclimating to humans and so don't get stressed when in their presence
or if human presence weeded out those stress-sensitive penguins, leaving
the copers behind.CREDIT: Vincent Viblanc

Scientists studying king penguins on a sub-Antarctic island, along with
tourists, may be stressing the waddling, flightless birds, new research
suggests. However, it seems the penguins are getting used to their
human visitors.

The new study reveals how more than 50 years of human presence, or the
time since a permanent research station was set up, on Possession
Island, has impacted a major colony of breeding king penguins (Aptenodytes patagonicus),
called the "Baie du Marin" colony. Research reported last year on these
penguins found that flipper tagging was linked with fewer chicks and a
lower survival rate for the birds compared with untagged king penguins.

Turns out, according to the new study, penguins that are used to humans
being around didn't get too upset by noise and human-presence
stressors, though capturing these penguins for scientific measurements
did cause a stress surge, according to the study published this week in
the journal BMC Ecology.

"A central question for ecologists is the extent to which anthropogenic
disturbances (e.g. tourism) might impact wildlife and affect the
systems under study," lead researcher Vincent Viblanc of the University
of Lausanne in Switzerland said in a statement. "One of the major
pitfalls of such research is in forgetting that, from the perspective of
the wildlife studied, tourism and scientific research are not two
worlds apart."

In some ways, this island is perfect for studying stress in penguins.
That's because some parts of the Baie du Marin colony have been exposed
more intensely to humans than others, Viblanc told LiveScience. In
disturbed parts of the colony scientists and tourists, sometimes in
groups of tens, come into the presence of the penguins. A small number,
about 50 birds, in this area are captured and handled by scientists one
to five times each year. Meanwhile, another part of the colony is
relatively undisturbed, Viblanc said, with one to two visits per week by
scientists.

The
king penguins come ashore on the sub-antarctic island to breed each
year. Hundreds of the penguins waddle onto land to find a mate, and
hopefully, make some chicks.CREDIT: Pierre Bize

Viblanc and his colleagues compared 15 breeding penguins
in these disturbed areas with 18 undisturbed penguins. All of the
penguins were brooding a chick between 2 days and a month old.
To get a sense of the penguins' stress levels, the researchers measured
their heart rates in response to three stressors: two low-intensity
stressors that included a human approach to about 33 feet (10 meters)
and a loud noise, meant to mimic tourists, scientists and noises from
machines operating on the outskirts of the colony. The high-intensity
stressor involved capturing a penguin to simulate what happens when
scientists take direct measurements.

Compared with penguins from undisturbed areas, the disturbed penguins
were less stressed by noise and approaching humans; the increase in
heart rate above resting levels was much lower, 81 percent and 74
percent lower, in birds used to humans when they heard stressful sounds
and saw humans approaching, respectively.

However, following capture, the human-acclimated penguins' maximum
relative heart rate increased 42 percent higher than it did for
undisturbed birds, though it recovered faster afterwards.
"Penguins habituate to the distant presence of human observers in
disturbed areas, whereas they do not habituate to being captured,"
Viblanc wrote in an email to LiveScience. "This makes sense, as from an
adaptive perspective, stress responses enable the organism to deal with
life-threatening situations. Captures may indeed be assimilated as
predation events from the birds, whereas the distant presence of
observers poses no immediate threat."

Their findings can't tease out whether the lower heart-rate numbers in
the highly disturbed areas are a result of penguins becoming habituated
to human presence or if they are the result of a selection process. For
instance, have penguins whose "animal personalities" are more
susceptible to stress deserted these areas, leaving behind those that
are better at coping, the researchers wonder.

Tuesday, July 10, 2012

Scientists now understand the biological reasons for behavior Dr Levick considered to be "depraved"

Accounts
of unusual sexual activities among penguins, observed a century ago by a
member of Captain Scott's polar team, are finally being made public.

Details, including "sexual coercion", recorded by George
Murray Levick were considered so shocking that they were removed from
official accounts.

However, scientists now understand the biological reasons behind the acts that Dr Levick considered "depraved".
The Natural History Museum has published his unedited papers.

Mr Levick, an avid biologist, was the medical officer on
Captain Scott's ill-fated Terra Nova expedition to the South Pole in
1910. He was a pioneer in the study of penguins and was the first person
to stay for an entire breeding season with a colony on Cape Adare.

He recorded many details of the lives of adelie penguins, but
some of their activities were just too much for the Edwardian
sensibilities of the good doctor.

He was shocked by what he described as the "depraved" sexual
acts of "hooligan" males who were mating with dead females. So
distressed was he that he recorded the "perverted" activities in Greek
in his notebook.

Graphic account

On his return to Britain, Mr Levick attempted to publish a
paper entitled "the natural history of the adelie penguin", but
according to Douglas Russell, curator of eggs and nests at the Natural
History Museum, it was too much for the times.

"He submitted this extraordinary and graphic account of
sexual behaviour of the adelie penguins, which the academic world of the
post-Edwardian era found a little too difficult to publish," Mr Russell
said.

Pages from Dr Levick's notebook with some sections coded in Greek

The sexual behaviour section was not included in the official
paper, but the then keeper of zoology at the museum, Sidney Harmer,
decided that 100 copies of the graphic account should be circulated to a
select group of scientists.

Mr Russell said they simply did not have the scientific
knowledge at that time to explain Mr Levick's accounts of what he termed
necrophilia.

"What is happening there is not in any way analogous to
necrophilia in the human context," Mr Russell said. "It is the males
seeing the positioning that is causing them to have a sexual reaction.
"They are not distinguishing between live females who are
awaiting congress in the colony, and dead penguins from the previous
year which just happen to be in the same position."

Sexual coercion

Only two of the original 100 copies of Mr Levick's account
survive. Mr Russell and colleagues have now published a
re-interpretation of Mr Levick's findings in the journal Polar Record.
Mr Russell described how he had discovered one of the copies by accident.

"I just happened to be going through the file on George
Murray Levick when I shifted some papers and found underneath them this
extraordinary paper which was headed 'the sexual habits of the adelie
penguin, not for publication' in large black type.

"It's just full of accounts of sexual coercion, sexual and
physical abuse of chicks, non-procreative sex, and finishes with an
account of what he considers homosexual behavior, and it was
fascinating."
The report and Mr Levick's handwritten notes are now on
display at the Natural History Museum for the first time. Mr Russell
believes they show a man who struggled to understand penguins as they
really are.

"He's just completely shocked. He, to a certain extent, falls
into the same trap as an awful lot of people in seeing penguins as
bipedal birds and seeing them as little people. They're not. They are
birds and should be interpreted as such."

Since no penguins live on the elevated lakeside site in East Antarctica, the researchers had to work out where the mysterious seabird poo came from.

They realised that their moss beds were growing on the site of an ancient penguin colony.

"Between 3,000 and 8,000 years ago, on the site where the moss is now growing, there used to be [Adelie] penguins," said Prof Robinson.

"There's fossil evidence to support that, and the little pebbles that the penguins use to make their nests are actually still there.

"The other thing that's still there is the penguin poo.

Six different species of moss live on the islands of East Antarctica studied by the scientists "And because Antarctica is so cold, those nutrients have just stayed frozen in the soil; they're now feeding this moss."

Prof Robinson said that the hardy plants, which grow just 2-3mm per year, create "luxuriant green beds" that are home to some of the insects and other miniature creatures that manage to live in this frozen desert.

Prof Robinson hopes to learn exactly how they adapt to this extreme environment.

The mosses are able to "freeze-dry" in order to survive the winter and produce sunscreen compounds to protect themselves from UV rays.

"It's amazing that the plants can do [these things], but it's also interesting to know which compounds they use," said Prof Robinson.

Learning the molecular mechanisms behind plants' abilities to dry out but remain viable could help researchers to develop ways to store food or even medicines for long periods.

ScienceDaily (July 2, 2012) —
A new species of feathered dinosaur discovered in southern Germany is
further changing the perception of how predatory dinosaurs looked. The
fossil of Sciurumimus albersdoerferi,which lived about 150
million years ago, provides the first evidence of feathered theropod
dinosaurs that are not closely related to birds.

The fossil is described in a paper published in the Proceedings of the National Academy of Sciences on July 2.

"This is a surprising find from the cradle of feathered dinosaur work, the very formation where the first feathered dinosaur Archaeopteryx
was collected over 150 years ago," said Mark Norell, chair of the
Division of Palaeontology at the American Museum of Natural History and
an author on the new paper along with researchers from Bayerische
Staatssammlung für Paläontologie und Geologie and the Ludwig Maximilians
University.

Theropods are bipedal, mostly carnivorous dinosaurs. In recent years,
scientists have discovered that many extinct theropods had feathers.
But this feathering has only been found in theropods that are classified
as coelurosaurs, a diverse group including animals likeT. rexand birds.
Sciurumimus -- identified as a megalosaur, nota coelurosaur --
is the first exception to this rule. The new species also sits deep
within the evolutionary tree of theropods, much more so than
coelurosaurs, meaning that the species that stem from Sciurumimus are likely to have similar characteristics.

"All of the feathered predatory dinosaurs known so far represent
close relatives of birds," said palaeontologist Oliver Rauhut, of the
Bayerische Staatssammlung für Paläontologie und Geologie. "Sciurumimus is much more basal within the dinosaur family tree and thus indicates that all predatory dinosaurs had feathers."

The fossil, which is of a baby Sciurumimus, was found in the
limestones of northern Bavaria and preserves remains of a filamentous
plumage, indicating that the whole body was covered with feathers. The
genus name ofSciurumimus albersdoerferirefers to the scientific name of
the tree squirrels,Sciurus, and means "squirrel-mimic"-referring to the
especially bushy tail of the animal. The species name honours the
private collector who made the specimen available for scientific study.
"Under ultraviolet light, remains of the skin and feathers show up as
luminous patches around the skeleton," said co-author Helmut
Tischlinger, from the Jura Museum Eichstatt.

Sciurumimusis not only remarkable for its feathers. The skeleton,
which represents the most complete predatory dinosaur ever found in
Europe, allows a rare glimpse at a young dinosaur. Apart from other
known juvenile features, such as large eyes, the new find also confirmed
other hypotheses.

"It has been suggested for some time that the lifestyle of predatory
dinosaurs changed considerably during their growth," Rauhut said.
"Sciurumimus shows a remarkable difference to adult megalosaurs in the
dentition, which clearly indicates that it had a different diet."

Adult megalosaurs reached about 20 feet in length and often weighed
more than a ton. They were active predators, which probably also hunted
other large dinosaurs. The juvenile specimen of Sciurumimus, which was
only about 28 inches in length, probably hunted insects and other small
prey, as evidenced by the slender, pointed teeth in the tip of the jaws.

"Everything we find these days shows just how deep in the family tree
many characteristics of modern birds go, and just how bird-like these
animals were," Norell said. "At this point it will surprise no one if
feather like structures were present in the ancestors of all dinosaurs.

The study was financed by the Volkswagen Foundation and the American Museum of Natural History.